More than 27,000 people came to 515 Alive at Water Works Park this weekend, up nearly 12,000 more people than last year. The music festival is in its 15th year, and it’s the first time it was held at Water Works Park. “This is a really unique festival for Des Moines,” said Tom Zmolek, 515 Alive event manager. “We have lots of music festivals, and this one is actually the longest running, it’s the 15-year anniversary and it’s the largest musical festival as of this weekend.” The festival grounds were open until 11 p.m. Saturday, and a silent disco continued into early Sunday.